It would have been an uncomfortable experience, coming face-to-face with the sheer scale of what we threaten by patrolling our nuclear weapons day in day out under the sea.

After all, there’s no point in having them if we aren’t willing to use them, and there’s no question that if we use them hundreds of thousands, perhaps millions of innocent civilians would die.

Should we be patrolling with nuclear weapons when we face no current strategic threat and see ourselves as a constructive force for good in the world? At the very least it demands that we re-double our efforts to work with fellow nuclear-armed states to rid the world of these weapons.

And that starts with some searching questions around why we are investing such a major proportion of our defence budget on Trident replacement (a third of the defence procurement budget over the next 15 years) and running costs (£2bn a year) whilst dramatically cutting back on other public expenditure.

One option amongst several would be to take our nuclear submarines off continuous patrol – they’ve been out for 25 years since the end of the Cold War, at huge expense, and yet those nuclear missiles have not been targeted on anyone.

They are there because we cannot be sure that a new threat might not emerge for which planners think a nuclear deterrent threat could be relevant. It is hard to establish particular scenarios that might fit such an activity, let alone ones which do not involve other allies that brandish their own nuclear weapons.

Abandoning continuous patrolling would not only send an important signal that the UK is prepared to take steps further down the nuclear ladder, it would also open up the possibility of further delay to decisions to replace the submarines, potentially saving the MoD and the taxpayer several billion.

Of course, to many people it doesn’t seem right to be talking about ‘abandoning’ our readiness to strike just when Russia is acting tough. What will vulnerable allies in Eastern Europe think if we appear to pull back?

But this is not about one man’s megalomania. President Vladimir Putin has high approval ratings in Russia precisely because actions by the ‘West’ have ignored the inevitable consequences of marginalising a state that still has daunting capacities to deliver major economic and strategic damage to the international community.

This is about a series of misjudgements over the last 20 years that all key states involved share. It is going to take a much deeper level of maturity to step out of the mutual traps we have developed with the Russians, and create a fresh reset that genuinely addresses their concerns (particularly the expansion of NATO, on missile defence and the development of destabilising conventional weapons).

Because right now we are headed towards a crisis in the international non-proliferation regime, of which the experience of the British in Vienna this week was only a brief and pleasant aperitif.

And falling out with the Russians not only harms the prospects for escaping an arms race with them and further belligerent actions on both sides, it harms the cooperation that is essential to deal with nuclear crises in South and East Asia and the potential for proliferation to the frightening unstable melting pot of the Middle East.